Process for preparing gelatinized propellent explosives.



UNITED STATES PATENT oFFIcE. I

FREDERIC LEWIS NATHAN AND WILLIAM RINTOUL, OF STEVENSTON, AND FRANK BAKER, DECEASED, LATE OFSTEVENSTON, SCOTLAND, BY HENRY BAKER ADMINIS- V TRATOR, OF ETON, WINDSOR, ENGLAND, ASSIGNORS TO NOBELS EXPLOSIVES COMPANY, LIMITED, OF GLASGOW, SCOTLAND;

1,302,202. No Drawing.

' LEwIs NATHAN and WILLIAM Rm'roun, both sub ects of the King of Great Britain and 7 Ireland, and residing at Ardeer, Stevenston,

. stabilizing of nitric-ester-containing explo- PROCESS FOR PREPARING GELATINIZED PROPELLENT EXPLOSIVES.

To all whom it may concern:

Be it known that we, Colonel Sir Fnunnmc Ayrshire, Scotland, and FRANK-BAKER, de-

ceased, late of Ardeer, Stevenston, Ayrshire,

Scotland, have invented a certain new and useful Improved Process for Preparing Gelatinized Propellent Explosives, of which the following is a specification.

Present da smokeless powders are generall prepared by gelatinizin nitrocellulose, either when used alone or witii nitroglycerin, by a volatile solvent but this entails certain disadvantages, the dr process for removing the solvent being engthy and, what is worse, besides tending owing to the heating to afiect the stability, is incomplete, so that during storage an after-drying and sloW production of irregularities in the material can occur.

In the course of investigations upon the sives we found that certain partially su bsti tuted ureas in which an aromatic radical oc curs (see United States application No.

.771620, Patent No. 1,090,6 l1 gran-ted March 17 1914,) are particularly adapted for use for stabilization but we have further found that among these bodies some are also efl'ective gelatinizers for mixtures of nitroglycerin and nitrocelluloses.

According to the present invention therefore we utilize one or more such substances to produce a gelatinized propellent explo-' sive from these nitric esters, the elatinizer remaining in the final product an acting as stabilizer.

The followin is a list of some of the sub stances referre to which possess this double tives of these substances ossess like properties. Thus the substitutlon of a methyl for an ethyl group or of a hydrogen atom in a phenyl group by the grouping O.CH or -().(],H in one of the above compounds but little affects their gelatinizing and stabilizing power.

Specification of Letters Patent.

Patented Apr. 29, 1919.

Application filed February 26, 1914. Serial No. 821,835.

In carrying the invention out in one way :15 parts by weight of the selected gelatini'zing and stabilizing agent are dissolved in 40 parts of nitroglycerin and this solution.

then incorporated by the wet incorporation method of Lundh'olm English Patent No..

10376 of 1889 with 52.5 parts of soluble nitrocellulose of 12.6% nitrogen content which has been prepared by nitrating cotton waste at the ordinary temperature, and purified by boiling with water.

The pasty admixture so obtained is freed as far. as pomible from water by pressing nizin'g effect and the solution of the material to be used in any particular case also depends largely upon the nature of the nitrocellulose to be treated, a powerful gelatinizer like methyl phenyl urea being more suitable for gun cotton or insoluble nitrocellulose than weak gelatinizers which may be quite satisfactory for nitrocellulose of the kind employed .in making celluloid. Again the greater the proportion of nitrocellulose in the mixture the more efieotive the gelati-' nizer, which has both to colloid the fibrousnitro-cellulose and to increase the plasticity of the final product, should be.

As certain of the bodies are better gelatinizersthan stabilizers or vice versa it may be convenient to use mixtures thereof, the poorer gelatinizing power of the one locing compensated by the better gel'atinizmg power of the other and vice versa as regards their stabilizing efi'ects. The amount of the gelatinizing and stabilizing agent or agents used will vary but generally be between 5 and 12% of the whole mixture.

:The physical properties of the agent or agents used will afiect the above method of introduction into the mixture for while liquid bodies are easily dissolved in the nitroglycerin, solids require to be finelyground and thoroughly agitated with the nitroglycerin or to be melted, if of low fusing point, and so added to the nitroglycerin. By admixture the melting point may be reduced, a mixture of some of these bodies which separately are solid being more or less liquid at temperatures but little above normal. Where the substance or substances used is or are soluble in water and the Wet incorporation method is used, the suspension should be effected in a solution of the substance-or substances of such strength that having regard to the mixture used the rlght final composition results. Thus for a mixture of nitroglycerin, of soluble nitrocellulose (12.6% nitrogen) and 10%- elatinizer the suspension should be efected in a 3.86% solution of methyl phenyl urea where the latter is used as and stabilizing agent.

Having now described our invention,

what we claim as new and desire to secure by Letters Patent'is l. The process for producinga gelatinized and stabilized propellent exploslvewhich comprises mixing together nitroglycerin, .ni-

trocellulose and a urea derivative containingstin the amido groups at least one un su ituted hydrogen atom, and. at least one aromatic radical capable both of gelatinizing nitrocellulose and of stabilizing nitric esters, and asecond body also possessing both-- these properties one of the latter two 35 bodies possessing the first mentioned property to'a smaller extent and the second mentioned property to a larger extent than the second mentioned body, and then gelatinizing the mixture. 40.

2. The process for producing a gelatir nized and stabilized propellent explosive which comprises mixing together nitroglycerin, nitrocellulose and methyl henyl urea capable both of gelatinizing mtrocel lulose and of stabilizing nitric esters, and a second body also possessing both these properties one of the latter two 'bodies possessing gelatinizing lizing the first mentioned prop'ert'y. to a smallerextent and the secondmentioned property to a larger extent than thesecond mentioned body, and then gelatinizing the mixture.

3. A gelatinized and stabilized" propellent.

explosive comprising nitroglycerin, nitrocellulose and a urea derlvatlve contalnlng 1n the amido groups at least one unsubstltuted hydrogen. atom, andat least one aromatic radical capable both of gelatinizing 4. A gelatinized and stabilized propellent explosive comprising nitroglycerin, nitrocellulose and methyl phenyl urea capable both .of gelatinizing nitrocellulose and of stabilizing nitric esters, and 'another stabiand gelatinizing compound also possessing both these properties one of the two gelatinizing and stabilizing compounds possessing the 'first mentioned property to a smaller extent and .the second. mentioned property to a larger extent than the other' gelatinizing and stabilizing compound.

In testimony whereof we have signed our names to this specification in the presence of subscribing witnesses.

FREDERIG LEWIS NATHAN. WILLIAM RINTOUL.

Witnesses:

M.- B. MITRIE, ALEX FoRBEs. v I

- HENRY BAKER,

Bake r, deceased. Witnesses: V I BER'1'RAMI H. MATT EWS,

P. A.- OUTHWAITE.

Administrator of the estate of Frank 

